* Add get and set position methods to all schematic items.
* Encapsulate schematic item position members.
* Add swap data method to schematic items that lacked one.
* Remove global swap data function used by undo and redo functions.
* Unify as many schematic move methods as possible.
* Remove unnecessary place schematic item methods.
* All schematic items are now moved in the same event handler.
* Fixed bug in hierarchical sheet get menu item string method.
* Make no connect and junction items movable, fixes lp:804048